The long-range goal of this investigation is to elucidate the mechanisms for the regulation of ribosome biosynthesis in Escherichia coli and how it is coordinated with the overall regulation of growth. The immediate goal is to characterize the transcription units for the ribosomal protein genes located at the str-spc and rif regions of the chromosome. Both regions contain genes for ribosomal proteins, RNA polymerase subunits, and translational elongation factors. Transducing phages carrying DNA from these regions will be used extensively in this investigation. One of our specific goals is to determine whether the ribosome and RNA polymerase genes in these clusters are cotranscribed and coordinately regulated. One approach to be taken is to determine whether polar mutations that reduce the expression of the polymerase genes also reduce the expression of the adjacent ribosomal protein genes. The mutations will be isolated on transducing phages and the expression of the genes will be studied by analysis of proteins synthesized after phage infection of ultraviolet light-irradiated bacteria. We will also investigate whether the syntheses of the beta and beta' subunits of polymerase are stimulated by the synthesis of the alpha subunit, and whether the synthesis of rRNA is stimulated by the synthesis of ribosomal proteins. We will attempt to determine the order of the genes in the Ery ribosomal protein transcription unit by isolating a series of transducing phage mutants containing insertions at different positions in the unit. Polar point mutants in the Str ribosomal protein transcription unit will be analyzed to see if they are nonsense mutants or promoter mutants. We will test whether the regulatory elements for the stringent control of ribosomal protein genes are associated with their bacterial promoters by determining whether they are still under stringent control when they are expressed from phage promoters. Finally, characterization of the mRNA for the ribosomal protein transcription units at the str-spc region and the interaction of RNA polymerase with the promoters for these units will be initiated.